1. Field of the Invention
This invention relates to articles prepared from novel anionic block copolymers of aromatic vinyl compounds and conjugated dienes, and to blends of such block copolymers with other polymers. The invention also relates to formed articles and methods for forming articles from such novel block copolymers.
2. Background of the Art
The preparation of block copolymers of mono alkenyl arenes and conjugated dienes is well known. One of the first patents on linear ABA block copolymers made with styrene and butadiene is U.S. Pat. No. 3,149,182. Over the last forty plus years a large number of new styrene diene polymers have been developed. Such polymers include linear polymers, radial polymers, asymmetric polymers, hydrogenated polymers, functionalized polymers and the like. In most cases the polymer was developed to meet an important customer need that is not currently being met. This has been a very dynamic process, and has resulted in enormous growth for new styrene/diene block copolymers and new uses to meet consumer demands.
In EP Patent Application Serial Number 04101527.2 filed on Apr. 14, 2004 in the EPO, a novel polymer is disclosed that found particular utility as an asphalt binder. This resulted in a reduction in drain-down, while maintaining proccessability at all stages of blending, mixing, laying and compaction, using standard available equipment. This novel polymer is actually a mixture of polymers, and comprises 5 to 70% by weight of a linear and/or radial styrene/diene block copolymer having a relatively high molecular weight, and 95 to 30% by weight of a styrene/diene diblock copolymer having lower molecular weight. Methods for making such polymers are described in detail in the above-mentioned patent application.
What has now been found is that blends or compounds of these novel block copolymer mixtures with processing oils and other polymers have surprising property advantages, and show promising utility in a variety of end-use applications, including injection molding, extruded goods and polymer modification.